FreeCAD MCP Server

What is FreeCAD MCP Server?

The FreeCAD MCP Server is a Model Context Protocol server that enables AI assistants to interact with FreeCAD for 3D modeling and CAD operations. It provides tools for geometry creation, boolean operations, document management, and custom script execution.

How to use FreeCAD MCP Server?

Install FreeCAD and Node.js 18+, clone the repository, run npm install, npm run build, and npm start. Then configure the server in your MCP client (e.g., Claude Desktop) by adding the path to build/index.js in the client’s claude_desktop_config.json.

Key features of FreeCAD MCP Server

• Create boxes, cylinders, and spheres with specified dimensions
• Perform union, cut, and common boolean operations
• Save documents and list objects in the current document
• Execute arbitrary Python scripts in FreeCAD’s context
• Cross-platform support for Windows, macOS, and Linux

Use cases of FreeCAD MCP Server

• Generate 3D models by asking an AI assistant to create and combine shapes
• Parametric design by having the AI adjust dimensions and parameters dynamically
• Build multi‑part assemblies using boolean operations between objects
• Automate CAD workflows through custom Python scripts run in FreeCAD

FAQ from FreeCAD MCP Server

What are the prerequisites for running this server?

FreeCAD must be installed on your system, along with Node.js version 18 or higher. TypeScript is required for development.

How do I configure the FreeCAD path if auto‑detection fails?

The server attempts to auto‑detect the FreeCAD installation, but you can manually update the freecadPath in the server constructor. Default paths are provided for Windows, macOS, and Linux.

What tools does the server expose?

The server provides seven tools: create_box, create_cylinder, create_sphere, boolean_operation, save_document, list_objects, and execute_python_script. Each tool accepts a JSON argument object.

How can I run a custom Python script in FreeCAD?

Use the execute_python_script tool with a script argument containing valid Python code. The script runs in FreeCAD’s Python interpreter, giving access to the document (doc) and FreeCAD API.

Does the server work with Claude Desktop?

Yes. The README includes an example configuration snippet for Claude Desktop’s MCP client. You add the server to ~/Library/Application Support/Claude/claude_desktop_config.json with the command set to node and args pointing to the built index.js file.